Structured Query Language (SQL)

Which SQL statement is used to update existing records in a table?

• CHANGE

• MODIFY

• UPDATE

Can the result of a SELECT statement contain duplicate rows?

• Yes

• No

What does a NULL value represent in SQL?

• It is treated as a blank or zero

• It is treated as a non-existent value

• It is treated as a negative value

In SQL, the truth value of (FALSE OR NULL) is...

• TRUE

• FALSE

• NULL

A relation may have multiple foreign keys.

• Yes

• No

You’re creating a table for a pizza delivery app.

Which CHECK constraint makes the least sense?

• CHECK (

  pizza_size IN ('Small', 'Medium', 'Large'))

• CHECK (

  delivery_time > CURRENT_TIMESTAMP)

• CHECK (

  topping_count >= 0)

• CHECK (price > 0)

Which of the following is true about SQL joins?

• An outer join returns only matching rows

• An inner join returns the results of the outer join as well as the unmatched rows

• A full outer join returns results of an inner join as well as the results of a left and right join

• None of these is true

What is the purpose of the GROUP BY clause in SQL?

• To sort the results of a query

• To aggregate data across multiple records

• To filter records based on a condition

What is the default sorting order of the ORDER BY clause in SQL?

• Ascending

• Descending

You realize your CREATE TABLE statement forgot to add a column for "favorite_movie".

What’s the best way to fix this?

• Delete the table and start over.

• Use ALTER TABLE to add the column.

• Cry and hope the problem goes away.

• Ignore the request; a table cannot be changed after creation.